Yes, they could have cracked the glass at the bottom while working there, very possible.

The heater core could be leaking or the A/C evaporator drain tube is clogged.

Is it an automatic or a stick?

I've found sun roofs on these Saturns is the weakest design I saw. Went to junk yard and assembled one working from a couple used. Had to take off the whole unit. (If you buy it as is from dismantlers it'll probably be partly or non-op.) Yet, I had to do same repair second time (was not careful - or lucky? using it at first) but now it works long time already without a ptoblem - that's after I started to respect it (Like not playng with it on-of driving 60 m/h -air/pressure on it); still works today even after I jammed it driving with the friends. On one of the next days I "helped it" back into position by hand (back-forth a few times) and that returned it to normal. Surprisingly, since as I said It is quite volnarable design (plus I already have epoxy -fixes in mine ...for worse or ...better then original..?)

Try the AutoMD website and the 'How-To-Guides' for the specific steps to replace the headlamp assembly.